The present invention relates to a silylation treatment unit and a silylation treatment method for performing a silylation treatment on a surface of a substrate, such as a semiconductor wafer or an LCD substrate.
In manufacturing a microelectronic device, such as a semiconductor integrated circuit, much higher performance is required for the lithography technology and the resist material being used, as the pattern being processed on the silicon wafer becomes finer.
With regard to the lithography technology being used for manufacturing the device, the wavelength of the light used for exposing the pattern is becoming shorter with both an i-ray source and a KrF excimer laser source being used.
The lithography is performed with the i-ray by using a photosensitizer of a novolac resist as a base resin. However, when using an excimer laser source to provide the shorter wavelength, the required fineness can not be achieved because the novolac resist has a high light absorption characteristic. Therefore, a resist using a phenolic ring compound has been suggested as a substitute. Although such a phenolic resist has an advantage in increased plasma resistance, the phenolic resist has an extremely high light absorptance, especially as the wavelength becomes shorter. Thus, light of short wavelength does not reach deep enough when an excimer laser light source is used.
A silylation method is a method having enough sensitivity and an improved plasma resistance, even when the light source used has a short wavelength, such as that of the excimer laser light source with this silylation method, a resist pattern having enough selectivity can be formed by exposing the photosensitizer to a predetermined pattern image, performing a silylation on the surface of thus-exposed photosensitizer, and performing dry developing using the silylation treated photosensitizer as a mask.
There is a problem, however, that the silylation reaction of the silylation method has an extremely high temperature dependency, such that the silylation reaction progresses ununiformly within the surface of a wafer if the temperature within the surface of the wafer is ununiform. Therefore, it is necessary to insure the uniformity of the silylation layer in order to employ the silylation method. To solve this problem, various conventional measures have been taken relative to hardware structures, such as the structure of the treatment chamber, the supplying method for the silylation atmosphere, and using a precision hot plate. However, even though the uniformity of the silylation layer can be improved by these measures, a minute defect in the hardware structure can prevent the uniform formation of the silylation layer, since its processing condition depends on the hardware.